IPC-T-50F_.pdf.pdf - 第36页

Geometric Tolerance 22.0568 A tolerance that is used to control form, proﬁle, orientation, location and runout. Gerber Data 25.1411 A type of data that consists of aperture selection and opera- tion commands and dimensio…

Forward Crosstalk 21.1406

Noise induced into a quiet line, as seen at the end of the

quiet line that is the farthest from the signal source,

because the quiet line has been placed next to an active

line. (See also ‘‘Backward Crosstalk.’’)

Fractional-Factorial Experiment 91.0550

An experiment whereby only a portion of the complete

factorial is run.

Frame Pitch 74.0551

The distance from the centerline of one tape-automated

bonding frame to the centerline on the next frame site on a

reel of carrier tape.

From-To List 21.0553

Written instructions in the form of a list that indicates the

locations of wiring terminations.

Fully Additive Process 53.1407

An additive process wherein the entire thickness of

electrically- isolated conductors is obtained by the use of

electroless deposition. (See also: ‘‘Semi-Additive Pro-

cess.’’)

Fully-Electroless Process 53.0554

see ‘‘Fully-Additive Process.’’

Functional Tester 92.0556

Equipment that analyzes the unit under test as a complete

functional entity by applying inputs and sensing outputs.

Functionality, Resin or Curing Agent 41.0555

The number of reactive groups per molecule.

Fused Coating 56.0557

A metallic coating, usually a tin or solder alloy, that has

been melted and solidiﬁed to form a metallurgical bond to

a basis metal.

Fusing 56.1676

Melting of a metallic coating (usually electrodeposted tin

or tin-lead) on a conductive pattern, followed by solidiﬁca-

tion

Fusing Fluid 56.0467

The heat-transfer medium used to attain a fused coating.

Fusing Flux 56.1408

An activated organic ﬂuid that is used in the fusing of a

tin-lead plating on a basis metal. (The application of these

predominantly water- soluble ﬂuids is usually followed by

the use of a fusing oil.)

Fusing Oil 56.1409

An thermally-stable, nonactivated, ﬂuid that is used in the

fusing of tin lead plating on a basis metal. (The application

of these predominantly water-soluble ﬂuids is usually pre-

ceded by the use of a fusing ﬂux.)

Galvanic Corrosion 76.1410

Corrosion associated with the current of a galvanic cell

consisting of two dissimilar conductors in an electrolyte or

two similar conductors in dissimilar electrolytes.

Galvanic Deposition 53.0560

see ‘‘Electrodeposition.’’

Galvanic Displacement 53.0561

see ‘‘Immersion Plating.’’

Gang Bonding 74.0562

The making of several terminations simultaneously. (See

also ‘‘Single- Point Bonding.’’)

Gas Blanket 75.0564

A ﬂowing inert gas atmosphere used to keep metallization

from oxidizing.

Gas-Tight Area 97.0563

The common area between mated-metal surfaces from

which gas vapors and impurities are excluded.

Gauge Precision 22.0559

The absolute precision achieved in measuring feature size

or feature location.

Gaussian Distribution 94.1807

See ‘‘Normal Distribution’’

Gel Time 55.0566

The time in seconds required for prepreg to change its

physical state from that of a solid material to a liquid, and

then back to a solid material.

Gelation Particle 44.0565

Microparticles of precured, usually transluscent, resin in a

laminate system.

Generative Process Planning 91.0567

A computer-based method whereby new process plans are

created that are based on part or product information and

manufacturing capabilities.

Generic Specification (GS) 26.1782

A document that describes as many general requirements as

possible, pertaining to a set, family or group of products,

materials, or service.

June 1996 IPC-T-50F

Geometric Tolerance 22.0568

A tolerance that is used to control form, proﬁle, orientation,

location and runout.

Gerber Data 25.1411

A type of data that consists of aperture selection and opera-

tion commands and dimensions in X- and Y-coordinates.

(The data is generally used to direct a photoplotter in gen-

erating photoplotted artwork.)

Glass Binder 44.0569

Glass powder added to a thick-ﬁlm resistive or conductive

ink in order to bind together the metallic particles after ﬁr-

ing

Glass Transition Temperature 55.1412

The temperature at which an amorphous polymer, or the

amorphous regions in a partially-crystalline polymer,

changes from being in a hard and relatively-brittle condi-

tion to being in a viscious or rubbery condition.

Go/No-Go Test 92.0570

A testing process that yields only a pass or a fail condition.

Golden Assembly 92.0571

see ‘‘Know Good Assembly

Golden Board 92.0572

see ‘‘Known Good Board’’

Gouge 92.0573

A form of wear that consists of a wide groove deformation,

accompanied by material removal, that penetrates a consid-

erable distance below a surface.

Graded Wedge 54.0574

see ‘‘Etching Indicator.’’

Grading Frame 44.0575

Equipment used to continuously inspect fabric by the use

of backlighting.

Green Strength 56.0577

The strength of substance, joint, or assembly before it has

been cured (set).

Greige 44.0578

Fabric in a loom state that has no ﬁnish.

Grey-Scale Processing 92.0576

The utilizing of more than one level of signal strength,

intensity or amplitude to perform an inspection operation.

Grid 22.1812

An orthogonal network of two sets of parrallel equidistant

lines that is used for locating points on a printed board.

Gross Leak 95.0580

A leak in a sealed package that is greater than 0.00001

cubic centimeters per second at one atmosphere of differ-

ential air pressure.

Ground 20.0581

A common reference point for electrical circuit returns,

shielding, or heat sinking.

Ground Plane 20.1413

A conductor layer, or portion thereof, that serves as a com-

mon reference for electrical circuit returns, shielding, or

heat sinking. (See also ‘‘Signal Plane’’ and ‘‘Voltage

Plane.’’)

Ground Plane Clearance 22.1414

Removed portions of a ground plane that isolate it from a

hole in the base material to which the plane is attached.

(See Figure G-1.) (See also ‘‘Signal Plane’’ and ‘‘Voltage

Plane.’’)

Guarding 92.0582

The in-circuit testing process of ensuring that a shunt path

does not interfere with the testing of a device.

Guide Pin 37.0583

A connector interfacing device that allows for connector

body movement in order to facilitate contact alignment

prior to contact engagement.

Gull Wing Leads 36.1747

An SMT lead form. Leads extending horizontally from the

component body centerline, bent downward immediately

past the body and then bent outward just below the bottom

of the body, thus forming the shape of a gull’s wing.

IPC-I-001031

Figure G–1 Ground (or voltage) plane clearance

Through Hole

Ground-Plane

Clearance

Nonfunctional

Land

Conductive

Pattern

Ground-Plane

Clearance

Through Hole

Conductive

Pattern

IPC-T-50F June 1996

Halide Content 76.0584

The ratio of the mass of free halides to the mass of solids

in a ﬂux, expressed in mass percent of free chloride ion.

Haloing 51.1415

Mechanically-induced fracturing or delamination, on or

below the surface of a base material, that is usually exhib-

ited by a light area around holes or other machined fea-

tures.

Hand Soldering 75.0585

Soldering using a soldering iron or other hand-held,

operator- controllable apparatus.

Hard Wiring 75.0587

Electrical wiring that is inseparable from an assembly with-

out the use of special tools and processes.

Hardeners 56.0586

see ‘‘Curing Agent.’’

Haywire 37.0588

A discrete electrical connection that is added to a printed

board in order to modify the basic conductive pattern

formed on the board. (See also ‘‘Jumper Wire.’’)

Header (Connector) 37.0589

A pin ﬁeld that is positioned in a 3- or 4-sided plastic

housing that mounts directly onto a printed board.

Header (Module) 36.0590

The base of an electronic component package that contains

leads.

Heat Cleaning 44.0591

A process in which organic yarn binder (size) is removed

from a fabric. (See also ‘‘Sizing.’’)

Heat Column 75.0592

The heating element in a eutectic die bonder or wire

bonder that is used to bring the base material up to its

bonding temperature.

Heat of Fusion 56.0593

The quantity of heat required to convert a unit weight of

solid material to its liquid state.

Heatsink 30.0594

A mechanical device that is made of a high thermal-

conductivity and low speciﬁc-heat material that dissipates

heat generated by a component or assembly.

Heatsink Plane 22.0595

A continuous sheet of metal on or in a printed board that

functions to dissipate heat away from heat generating com-

ponents.

Heatsink Tool 75.1416

A heatsink that is temporarily attached to a heat-sensitive

component in order to minimize the transfer of heat from

the component lead to the component body during a solder-

ing operation.

Heavy Mark (Fabric) 44.0596

A ﬁlling defect that extends across the width of a fabric

containing in excess of two picks per inch from nominal.

Heel, Bonding 74.0598

The part of a lead adjacent to a termination that has been

deformed by the edge of the bonding tool.

Heel Break 97.0599

The rupture of a lead at the heel of a bond.

Heel Crack 97.0600

A crack across the width of a lead at the heel of a bond.

Heel (Drill) 51.0597

The trailing edge of a drill land

Helix Angle 51.0601

The angle of the spiral generated by the ﬂute of a drill with

respect to the axis of the drill.

Hermaphroditic Contact 37.0602

A type of connector contact that mates with a contact that

is identical to itself.

Heterocyclic 76.0603

A cyclic or ring structure, often in the shape of a pentagon,

in which one or more of the atoms in the ring is an element

other than carbon.

Hierarchical Database 11.0604

A database that is arranged in a tree-like structure of logic.

High-Impedance State 21.0605

see ‘‘Tri-State.’’

High-Voltage Wire 37.0606

Insulated wire, with an insulation thickness that is deter-

mined by corona-related factors, that is used for voltag es

over 240 Vac RMS or over 340 Vdc.

Hipot Test 92.0607

A method in which the unit under test is subjected to a high

alternating current (ac) voltage.

Histogram 91.0608

A graph that depicts values that were obtained by dividing

the range of a data set into equal intervals and that plots the

number of data points in each interval.

June 1996 IPC-T-50F